The MCU is Earth-199999, with a few exceptions. The X-men films (Including Deadpool) are mostly in Earth-10005. the Spider-man films have different Earths depending on the actor.
I get the feeling that they will remain separate, with a few actors crossing over to the MCU because of multiverse stuff.
Howard the Duck is in Earth-58470, assuming the TVA haven’t dealt with that embarrassment.
